-Wimplicit-int warnings in C code

[jzern]

@ 5f8911c

For example compiling with gcc 12.2.0:

iac/src/iamf_enc/dmpd/asc/src/kernels/strided_slice.c:217:15: warning: type defaults to ‘int’ in declaration of ‘strides’ [-Wimplicit-int]
  217 |   const auto* strides = params->strides;
      |               ^~~~~~~

The auto keyword in C is different from auto in C++11. Automatic storage duration is the default at block scope, this should be removed and the correct types used.

[jzern]

Many of these warnings are still present @ f48a939.